Professional partner notification is a successful and acceptable method of identifying new HIV infections, according to a study conducted in San Francisco and published in the December 1st edition of the Journal of Acquired Immune Deficiency Syndromes. Most of the patients whose partners were traced were gay men – a population where third-party partner notification is often difficult.
San Francisco has a Partner Services for HIV which provides comprehensive HIV prevention interventions including third-party notification services. The services is staffed by highly trained staff and confidentially notifies the named-partners of individuals with diagnosed HIV infection that they may have been exposed to HIV and offers counselling, HIV testing and referral to appropriate services.
Small studies have suggested that third-party notification is more successful at notifying partners than patient-initiated notification. But third-party notification is not routine in the US. Furthermore, experience of third-party notification with gay men, who often have anonymous sexual contacts, has not been encouraging.
Investigators from San Francisco therefore designed a prospective study to see how many new cases of HIV were identified by partner notification services amongst the contacts or sexual networks of three populations:
- Individuals diagnosed with acute HIV infection.
- Individuals diagnosed with non-acute HIV infection.
- Individuals with previously diagnosed chronic HIV infection who were diagnosed with syphilis.
The investigators hypothesised that as individuals with acute HIV infection have very high viral loads, a higher proportion of their partners would be found to be infected with HIV, followed by the partners of patients diagnosed with non-acute HIV and finally the partners of patients receiving HIV care who were diagnosed with syphilis.
Cost per new HIV infection detected using partner notification services was compared to the costs involved in detecting a single new HIV infection using traditional voluntary counselling and testing services. The cost of both these services were then compared to the cost effectiveness figure for routine HIV testing in general practice.
Between 2004 and 2006 a total of 763 individuals with newly diagnosed HIV, or long-standing HIV and syphilis, came into contact with partner notification services. The overwhelming majority (89%) were gay and 54% were white.
A total of 607 individuals (80%) agreed to an interview with partner notification staff and these individuals provided locating information for 907 partners (average 1.49 per patient).
These named partners represented 11% of acknowledged sexual contacts, including 3% (15 named-partners) of contacts of patients with acute HIV, 11% (339 named-partners) of contacts for non-acute HIV, and 19% (553 named-partners) of contacts for patients with a long-standing HIV diagnosis and syphilis.
As expected, patients with acute HIV infection had the highest proportion of named-partners who were also found to be HIV-positive (7%, one of 15). Furthermore, 4% of the named-partners of patients with non-acute HIV (15 of 339 individuals) were found to be HIV-positive as were 1% (seven of 553) named-contacts of patients with a long-standing HIV diagnosis and syphilis.
The number of contacts needing to be interviewed to detect a single case of HIV was 25 for the contacts of patients with acute HIV, 21 for patients with non-acute HIV, and 39 for patients with a long-standing HIV diagnosis and syphilis.
All but one of the new HIV infections identified using partner notification services were sexual contacts, the other individual was part of a sexual network.
The investigators noted that normal voluntary counselling and testing services involve a cost of $2300 per new HIV infection detected. The cost of identifying each new infection amongst the named-partners of patients with acute or non-acute HIV was $7081, but only $2600 for each new infection identified amongst the named-partners of patients with known HIV infection and syphilis. However, the investigators emphasise that all these figures are well below the $30,000 cost-effectiveness figure set for identifying each new case of HIV using routine HIV testing in general practice.
“Partner notification successfully identified new cases of HIV infection among a primarily gay/bisexual male HIV-infected population in San Francisco”, conclude the investigators, who add, “given the yield of newly identified HIV-infected individuals, third-party notification for HIV infection performed by well-trained staff should be further evaluated and potentially expanded locally and in other jurisdictions, including those with a high proportion of cases among gay men and other men who have sex with men.”
Ahrens K et al. HIV partner notification outcomes for HIV-infected patients by duration of infection, San Francisco, 2004 – 2006. J Acquir Immune Defic Syndr 46: 479 – 484, 2007.